An Electroencephalogram (EEG) is a tool used to measure electrical activity produced by the brain. The functional activity of the brain is collected by electrodes placed on the scalp. The EEG has traditionally supplied important information about the brain function of a patient. Scalp EEG is thought to measure the aggregate of currents present post-synapse in the extracellular space resulting from the flow of ions out of or into dendrites that have been bound by neurotransmitters. Accordingly, EEG and like modalities are mainly used in neurology as a diagnostic tool for epilepsy but the technique can be used in the study of other pathologies, including sleep disorders.
Recent advances in EEG and other signal detection have allowed for the automated, real time, detection of sleeping and waking states through the normalization and other manipulation of brain activity data. In addition, such applications and methods can also be used to automatically access pathological conditions and medication effects. Related technology has allowed for the accessing of such data in real time utilizing a single channel detector. This in turn has provided the opportunity to further dissect sleep and waking states, including clear differentiation between REM and deep sleep states. To aid in the efficient collections of such data, head and harness systems have been developed utilizing single channels and wireless data transmission. See, e.g., International Patent Application Number PCT/US2006/018120; International Patent Application Number PCT/US2009/064632; International Patent Application Number PCT/US2010/054346; U.S. Pat. No. 8,073,574; and Low, Philip Steven (2007). “A new way to look at sleep: separation and convergence”. Published Thesis, University of California San Diego Electronic Theses and Dissertations (Identified: b6635681), the disclosures of which are herein incorporated by reference in their entirety. To date, this technology has been primarily applied to sleep-related diagnostic applications, and the impact of pathologies and medications.
Development has continued in the area of exoskeletons and related prostheses that hold the promise to allow paraplegics to walk again and perform other tasks that they currently are unable to perform. In addition, such devices may also be useful with healthy individuals, such as soldiers in the field, first responders, construction works etc. Companies such as Esko Bionics, Parker Hannifan and Argo Medical Technologies and consistently advancing such technologies. See, e.g., U.S. Pat. No. 8,096,965; International Patent Application Number WO2010101595A1, and U.S. patent application Ser. No. 11/600,291, filed Nov. 15, 2006. In addition, other devices are utilized to allow severely compromised individuals with ALS, MS and the like to communicate using voice synthesizers and the like. Typically, such devices are activated by movement of a cheek muscle, eye using Eye Tracker or the like.
There is therefore a need for non-invasive methods to detect the intentional and unintentional communication from subjects, including disabled individuals, to assess and potentially respond to or prepare for the physiological implications of these changes in brain state.